Alkenyl succinimides of piperazines



Unit States atent 3,024 237 ALKENYL SUCCllNlMlbES OF PIPERAZINES Alan Y.Drnmmond, Richmond, Robert G. Anderson, Novato, and Frank A. Stuart,Orinda, Calif, assignors wherein R is a hydrocarbon radical having amolecular weight from about 400 to about 3000; that is, R is ahydrocarbon radical containing about 30 to about 200 carbon atoms; R isa hydrocarbon radical containing from II to California ResearchCorporation, San Francisco, 5 1 to 3 f and R 15 hydrogen or ahydrocarbon rad1cal contalnlng from 1 to 3 carbon atoms. Califi, acorporation of Delaware N0 Drawing Filed Aug 24, 1959 g 335 339 TheseN-substituted alkenyl SLlCClIlllTlldCS can be pre- 6 Claim (Cl, 260-268)pared by reacting maleic anhydride with an olefinic hydrocarbon,followed by reacting the resulting alkenyl suc- This invention pertainsto a new class of compounds 10 cinic anhydride with anN-(fi-aminoalkyl)piperazine. particularly useful as lubricating oiladdition agents. Such N-(B-aminoalkyl)piperazines are exemplified byThesednew compounds are N-substituted alkenyl suc- N methyl N, (paminoethyl)piperazine, 01mm] N-isopropyl-N'-(fi-aminoethyl)piperazine,

Alkenyl SllCCll'llC anhydrides and numerous derivatives N(lgfiminoisopronyl)piperazine thereof are well known in the art. Forexample, alkenyl succinic anhydrides in which the alkenyl radicalcontains The R radical of the above formula, that is, the from 5 tocarbon atoms are taught as corrosion inalkenyl radical, is derived froman olefin containing from hibitors in lubricating oil compositions.Also, products 2 to 5 carbon atoms. Thus, the alkenyl radical'isobobtained by reacting such alkenyl succinic anhydrides tained bypolymerizing an olefin containing from 2 to 5 with monoamines are taughtas ferrous corrosion. inhibi- 20 carbon atoms to form a hydrocarbonhaving a molecular tors for lubricating oil compositions. weight rangingfrom about 400 to about 3000. Such However, the above known alkenylsuccinimides are olefins are exemplified by ethylene, propylene,l-butene, not useful as detergents in lubricating oil compositions.Z-butene, isobutene, and mixtures thereof. Since the In contrastthereto, the N-substituted alkenylsuccinimides methods of polymerizingthe olefins to form polymers described herein are new compounds whichare useful thereof is immaterial in the formation of the new comasdetergents in lubricating oil compositions. v pound described herein,any of the numerous processes Thus, it is a primary object of thisinvention to preavailable can be used therefor. sent as new compounds,new alkenyl succinimides which The preparation of N-substitutedmonoalkenyl succinare particularly useful as detergents in lubricatingoil imides derived from amine derivatives of piperazine cancompositions. v be described generally by the following equations, usingIn accordance with this invention, it has been dis- 7 a polymer ofisobutene as an example of the alkenyl covered that N-alkylpiperazinemonoalkenyl succinimides radical, and N-(B- aminoethyl)piperazine as anexample derived from monoalkenyl succinic anhydrides and amine of anamine derivative of piperazine: 5

1 ll (I) (I111, ("JH (EH, CH-C\ 3H, (|3H on, CHFOOH2 'CH2(F GHQ-0:011: 00H,-0-oHz--oHr( J CH=COH:CHG\

O GHz-fil (II) CH3 ?H3\ $11 (I? CHr-CH: CHr-COH2CHr(IZCH=C-CH2CH=C\HzNCHaCHzN I N-H CHz/n /O CHz-C 2 Cl-I -C CH3 ()H3\\ ([3113 CHOCHgCH2(|3 CH=C-CH2CH-C CH2C2 GHQ/i. NCH2CH2N /NH tong-o onion,

derivatives of piperazine are new compounds which are gasoline engineparts remain remarkably free of deposits I and varnish even under severeoperating conditions.

These new compounds, which are monoalkenyl succinimides ofN-alkylpiperazines have the formula:

. ll R-CH-C wherein n has a value of about 7 to'about 5.0.

proceed in a mol ratio of the polyolefin to the m'aleic anhydride of 1:1to 1:10; preferably from 1:1 to 1:5 The reaction temperature can varyfrom 300 F. to 450 F.

Because of the greater yield of products obtained thereby,

it is preferred to use the higher temperature range (e.g.,

375 F. to 450 F.)

In the second step of the reaction as exemplified by Equation IIhereinabove, the yield of the imide is extremely high even though thereactants are used in equal molar ratios.

The reaction described by Equation II hereinabove can be made at 220 F.to 500 F., preferably from 300 F. to 400 F., preferably in an atmosphereof nitrogen. The alkenyl succinic anhydride and the piperazinederivative are reacted in about equal molar quantities.

Since the reaction between the polyolefin and maleic anhydride may notgo to completion, the resulting alkenyl succinic anhydride may containsome unreacted polyolefin. As it may not be desirable to separate outthis unreacted polyolefin at this stage, the resulting imide formed willcontain this polyolefin as an impurity which can be a diluent in theformation of lubricating oil compositions. However, if it is so desired,this unreacted polyolefin can be removed by precipitation, for example,by acetone or methanol from a hydrocarbon solution.

The preparation of the alkenyl succinimides of this invention isillustrated in the following examples.

EXAMPLE I Preparation of Polybutenyl Succinic Anhydriae A mixture of1000 grams (1 mol) of a polyisobutene having a molecular weight of about1000 and 98 grams (1 mol) of maleic anhydride was heated at 410 F. in anitrogen atmosphere with agitation for a period of 24 hours. Thereaction mixture was cooled to 150 F., and 700 cc. of hexane added;after which the mixture was filtered under vacuum. After vacuumdistillation to remove the hexane from the filtrate, the product wasmaintained at 350 F. at an absolute pressure of 10 mm. Hg for one hourto remove traces of maleic anhydride. The crude polybutenyl succinicanhydride thus prepared had a saponification number of 79.

EXAMPLE II Preparation of N-Ethylpiperazine Polybutenyl SuccinicAnhydride of Example I Hereinabove A mixture of 18 grams (0.14 mol) ofN-(B-aminoethyl)piperazine and 200 grams (0.13 mol) of the polybutenylsuccinic anhydride of Example I, hereinabove, was blended with agitationin a nitrogen atmosphere and heated to a temperature of 500 F., afterwhich the absolute pressure was reduced to about 200 mm. Hg to removeexcess amine reactant. The reaction mixture was then allowed to reachroom temperature at this reduced pressure. The reaction productcontained 2.59% nitrogen (theory 2.67%). Infra-red analysis showed thatthe reaction product was an imide containing a polybutene side chain.

The new compounds of this invention are more effective as lubricatingoil additives than alkenyl succinimides having fewer nitrogen atoms inthe amine portion of the molecule, and succinimides having less thanabout 30 carbon atoms in the alkenyl radical. The use of amylamine, forexample, in place of the above-identified aminoalkylpiperazine describedin this invention results in a product which is ineffective as adetergent in lubricating oil compositions.

As lubricating oil additives, the N-snbstituted alkenyl succinimides ofthis invention can be used in amounts of 0.1% to 80%, by weight,preferably 0.25% to by weight.

Table I hereinbelow sets forth data showing the effectiveness of the newcompounds of this invention as lubricating oil additives.

The monoalkenyl succmimide used was an N-substituted alkenyl succinimidederived from N-(fl-aminoethyl) piperazine wherein the alkenyl radicalhad a molecular weight of approximately 1000, which alkenyl radical wasa polymer of isobutene.

The tests were made in a Caterpillar L-1 engine accord- 4 ing toMilL-2104 conditions for a period of 120 hours as described in theCoordinating Research Council Handbook, Ianuary 1946.

The PD Nos. refer to the piston discoloration rating. After the enginetest, the three piston lands were examined visually. To a piston landwhich was completely black was assigned a PD number of 800; to one whichwas completely clean, a PD number of 0; to those intermediate betweencompletely black and completely clean were assigned PD numbersintermediate in proportion to the extent and degree of darkening.

The GD. Nos. refer to the percentage deposits in the piston ringgrooves; an 0 evaluation being a clean groove; and a number of being agroove full of deposits.

The base oils were California SAE 30 base oils.

TAB LE I Additive: succinimide, weight percent.--" 0.0 1.0 Test results:

G.D. No

It is readily seen from the data set forth hereinabove in Table I thatalkenyl succinimides derived from amine derivatives of piperazine asdescribed herein are effective as lubricating oil additives for thelubrication of internal combustion engines.

We claim:

1. The compounds, N-alkylpiperazine monoalkenyl succinimides whereinsaid alkenyl radical contains from 30 to 200 carbon atoms, and saidalkyl radical contains from 1 to 3 carbon atoms.

2. The compounds, N-alkylpiperazine monoalkenyl succinimides whereinsaid alkenyl radical is a polymer of an olefin containing from 2 to 5carbon atoms, said polymer having a molecular weight from 400 to 3000,and said alkyl radical contains from 1 to 3 carbon atoms.

3. The compound, Nalkylpiperazine monoalkenyl succinimide of theformula:

Hr-C

wherein R is a hydrocarbon radical containing from 30 to 200 carbonatoms, and R' is a hydrocarbon radical containing from 1 to 3 carbonatoms.

4. The compound,

II R-CH-C wherein R is a polyisobutene radical containing from 30 to 200carbon atoms and R is a hydrocarbon radical containing from 1 to 3carbon atoms.

5. The compound, N-alkylpiperazine monoalkenyl wherein R is apolyisobutene radical having a molecular weight of about 1,000.

6. The compound,

CHz-CH: l/n OH:CH;N NH

CHa-C CHr-C 2 lg wherein n has a value of about 7 to about 50.

References Cited in the file of this patent UNITED STATES PATENTS2,540,800 Trigg et a1 Feb. 6, 1952 2,628,942 Morris et a1 Feb. 17, 19532,904,548 Rice et a1. Sept. 15, 1959 OTHER REFERENCES Rice et al.: Jour.Amer. Chem. Soc. vol. 75, pp. 2261- 2262 (1953).

1. THE COMPOUNDS, N-ALKYLPIPERAZINE MONOALKENYL SUCCINIMIDES WHEREINSAID ALKENYL RADICAL CONTAINS FROM 30 TO 200 CARBON ATOMS, AND SAIDALKYL RADICAL CONTAINS FROM 1 TO 3 CARBON ATOMS.